Because of the small dimensions used in integrated circuitry, developing components in integrated circuitry which can withstand high voltage operation is difficult. An example is bipolar lateral transistors when incorporated with CMOS integrated circuit devices. Bipolar transistors in the same integrated circuit as complementary MOS transistors is commonly known as BiCMOS. BiCMOS fabrication processes are extremely complex and any simplification in the process or additional capability added using no additional processing steps is valuable. Lateral bipolar transistors are often included because of their ability to be easily integrated into other processes.
Lateral bipolar transistors are usually formed by using the diffusions for contacts or source/drains as collector and emitter and using a well of the opposite conductivity type as the base region. Contact to the well is provided by a buried contact region which is normally used with the higher quality vertical transistors. This process requires no additional steps to fabricate the lateral transistor and the lateral transistor can provide the opposite conductivity configuration to the vertical transistors. For example, using NPN vertical transistors, a PNP lateral transistor may be fabricated. However, the prior art configuration does not provide optimal operating characteristics. The base separation between the emitter and collector is dictated by the minimum field oxide dimensions in the integrated circuit. In addition, high voltage operation of the transistor is very limited.